104 TELEOSTEI : ACANTHOPTERI. XX. 



a. Ventral rays united into one ; D. low ...... TETRAPTURUS, 122. 



ao. Ventral rays 2 or 3; D. very high ....... ISTIOPHOKUS, 123. 



122. TETRAPTTTRUS Rafinesque. (rerpa-, four ; TrrepoV, fin; 

 ovpd, tail.) 



260. T. albidus Poey. SPEAR-FISH. BILL-FISH. Blue-black ; 

 head (with sword) 2f ; depth 7. D. Ill, 39-6. A. II, 13-6. L. 8 

 feet. W. L, N. to Cape Cod. (Lat., white.) 



123. ISTIOPHORUS Lacepede. (for/op, sail ; <opeo>, to bear.) 



261. I. americanus Cuv. & Val. SAIL-FISH. SPIKE-FISH. 

 Bluish-black; dorsal very high, its membrane with round black 

 spots. Sword, from eye, 2f times rest of head, nearly twice as 

 broad as deep. Head 2f ; depth 6. D. XLI - 7. A. 9-7. L. 6 to 

 8 feet. Warm seas, N. to Cape Cod. 



FAMILY LIV. TRICHIURIDuE. (THE SCABBARD-FISHES.) 



Fishes closely related to the Scombridce, but having the vertebrae 

 very numerous, and the dorsal fin long and low, its spines and soft 

 rays indistinguishable from each other, and without finlets. Ven- 

 tral fins rudimentary or wanting. Genera 6 ; species about 15, in 

 the warm seas. 



o. No caudal fin; tail tapering to a point; no ventrals; teeth very strong, 

 unequal, some of them barbed ......... TRICHIURUS, 124. 



124. TRICHIURUS Linnaeus, (rpi^iov, a little hair ; 



ovpd, tail.) 



262. T. lepturus L. SCABBARD-FISH. CUTLASS-FISH. SIL- 

 VER EEL. Silvery, D. dark-edged ; snout long ; lower jaw longer. 

 Head 7J; depth 16. D. 135. A. very low, 100. Warm sea, N. to 

 N. Y. (XeTTTcfc, thin ; otyd, tail.) 



FAMILY LV. SCOMBRIDJE. (THE MACKERELS. 



Body subfusiform or compressed, with small cycloid scales, those 

 at the shoulders sometimes enlarged, forming a corselet ; lateral line 

 present. Head pointed ; mouth large, not protractile ; teeth sharp, 

 large or small ; opercles unarmed; gill openings very wide ; pseudo- 

 branchiae large. Dorsals two, the first of slender spines, the second 

 usually followed by detached finlets ; tail slender, keeled, its fin 

 widely forked ; V. thoracic I, 5. Vertebrae in increased number, 30 

 to 70 ; pyloric caeca many. Coloration metallic, the sexes similar. 

 Genera about 1 7 ; species about 70. Fishes of the high seas, many 

 of them cosmopolitan, coming to northern shores to spawn, and 

 often irregular in their visits. Most of them are valued as food, 

 but the red, oily flesh of some is very coarse. 



